Constrained state-feedback control of an externally excited synchronous machine

State-feedback control of externally excited synchronous machines employed in applications such as hybrid electric vehicles and full electric vehicles is a challenging problem. Indeed, these applications are characterized by fast dynamics that are subject to hard physical and control constraints. The goal of this paper is to provide a controller synthesis method that can answer these challenges effectively. To this end, firstly, a linear control law is obtained for the unconstrained dynamics via a standard control Lyapunov function (CLF), along with an admissible basin of attraction. Then, a piecewise affine control law defined on a cubic partition of the state-space is obtained for the constrained dynamics via a flexible CLF. An a posteriori test for checking stability and invariance of a set of initial conditions for the resulting closed-loop dynamics is also proposed. The effectiveness of the developed synthesis method is demonstrated in a realistic simulation scenario

Efficient state reference generation for torque control in externally excited synchronous machines

A relevant challenge in hybrid electric vehicles and full electric vehicles is the torque control of externally excited synchronous machines. Effective torque control requires an efficient solution to the state reference generation problem, which is a nonlinear non-convex optimization problem. The goal of this paper is to develop a state reference generation algorithm based on the griding of the state and output spaces. Firstly, an approximation defined over a cubic partition of the torque function with a piecewise affine function is made. As a result, the state reference generation problem is reduced in each cube to solving a convex optimization problem. Moreover, this approach provides guarantees about the error bound introduced by the state reference generation procedure for the full operational state-space. To illustrate the effectiveness and robustness of the proposed algorithm several real-time results obtained on an industrial hardware in the loop test-bench are presented. The obtained results show significant improvement compared with existing state-of-the-art reference generation methods